Methods and products of amino acid isolation

Abstract

Embodiments of the present invention provide processes for extracting amino acids from mixtures of amino acids, and compositions and mixtures formed therefrom. Applications include separating and/or isolating non-aromatic amino acids, and/or separating aromatic amino acids into at least one fraction containing phenylalanine and tryrosine and a fraction containing L-β-3-indolylalanine (L-β-3) and providing natural or other amino acid mixtures thereof. The source of amino acids may include a natural source, such as an enzymatically hydrolyzed protein or other natural protein hydrolysates containing mixtures of free amino acids. The processes of embodiments of the present invention include contacting the mixture of amino acids with a resin or hydrophobic substance that is attractive to aromatic amino acids but not attractive to aliphatic amino acids to separate the aromatic amino acids from the rest of the mixture.

1 . A process, comprising: 
 providing an aqueous solution of a mixture of amino acids;    contacting a hydrophobic substance with the aqueous solution to form a first fraction comprising non-aromatic amino acids, wherein the hydrophobic substance is attractive to aromatic amino acids and has substantially no attraction to non-aromatic amino acids;    contacting the hydrophobic substance with a wash agent provided at a first flow rate to remove residual non-aromatic amino acids from the hydrophobic substance; and    increasing the flow rate of the wash agent to a second flow rate to remove monocyclic aromatic amino acids from the hydrophobic substance to form a second fraction.    
   
   
       2 . The process of  claim 1 , wherein said contacting a hydrophobic substance comprises contacting a polymeric resin.  
   
   
       3 . The process of  claim 1 , wherein said contacting a hydrophobic substance comprises contacting a resin selected from the group consisting of a porous resin, a non-ionic resin, a non-ionic porous resin, a non-ionic cross-linked polystyrene, a particulate-form resin, and a bead-form resin.  
   
   
       4 . The process of  claim 1 , wherein said flow rates are volume normalized.  
   
   
       5 . The process of  claim 1 , wherein said providing comprises providing the aqueous solution at a flow rate of approximately 2 to 5 gallons per minute.  
   
   
       6 . The process of  claim 1 , further comprising recovering at least one non-aromatic amino acid from the first fraction.  
   
   
       7 . The process of  claim 6 , wherein said recovering comprises at least one process selected from the group consisting of filtration, reverse osmosis, evaporation, centrifugation, and crystallization.  
   
   
       8 . (canceled)  
   
   
       9 . The process of  claim 1 , wherein said contacting the hydrophobic substance with a wash agent comprises contacting the hydrophobic substance with water.  
   
   
       10 . The process of  claim 1 , wherein said contacting the hydrophobic substance with a wash agent comprises contacting the hydrophobic substance with at least one acid.  
   
   
       11 . The process of  claim 1 , further comprising providing the wash agent at a first flow rate of approximately 2 to 5 gallons per minute.  
   
   
       12 . The process of  claim 1 , further comprising recovering at least one monocyclic aromatic amino acid from the second fraction.  
   
   
       13 . The process of  claim 12 , wherein said recovering comprises at least one process selected from the group consisting of filtration, reverse osmosis, evaporation, centrifugation, and crystallization.  
   
   
       14 . (canceled)  
   
   
       15 . The process of  claim 1 , further comprising combining at least a portion of the first fraction with at least a portion of the second fraction.  
   
   
       16 . The process of  claim 1 , further comprising recovering at least one monocyclic aromatic amino acid from the second fraction.  
   
   
       17 . The process of  claim 16 , wherein said recovering comprises at least one process selected from the group consisting of filtration, reverse osmosis, evaporation, centrifugation, and crystallization.  
   
   
       18 . (canceled)  
   
   
       19 . The process of  claim 1 , wherein said increasing the flow rate of the wash agent to a second flow rate comprises increasing the flow rate to approximately 8 to 11 gallons per minute.  
   
   
       20 . The process of  claim 1 , further comprising contacting the hydrophobic substance with a release agent to remove L-β-3 from the hydrophobic substance to form a third fraction.  
   
   
       21 . The process of  claim 20 , further comprising recovering L-β-3 from the third fraction.  
   
   
       22 . The process of  claim 21 , wherein said recovering comprises at least one process selected from the group consisting of filtration, reverse osmosis, evaporation, centrifugation, and crystallization.  
   
   
       23 . (canceled)  
   
   
       24 . The process of  claim 20 , further comprising combining at least a portion of the first fraction with a portion of the third fraction.  
   
   
       25 . The process of  claim 20 , wherein said contacting the hydrophobic substance with a release agent comprises contacting the hydrophobic substance with isopropyl alcohol.  
   
   
       26 . The process of  claim 20 , wherein said contacting the hydrophobic substance with a release agent comprises contacting the hydrophobic substance with at least one base.  
   
   
       27 . The process of  claim 20 , further comprising providing the release agent at a flow rate of approximately 8 to 11 gallons per minute.  
   
   
       28 . The process of  claim 20 , further comprising flushing the resin to remove residual L-β-3 from the hydrophobic substance.  
   
   
       29 . The process of  claim 28 , wherein said flushing the resin comprises flushing the resin with water.  
   
   
       30 . The process of  claim 28 , wherein said flushing the resin comprises flushing the resin at a flow rate of approximately 8 to 11 gallons per minute.  
   
   
       31 . A process, comprising: 
 providing an aqueous solution of a mixture of amino acids;    contacting a hydrophobic substance with the aqueous solution to form a first fraction comprising non-aromatic amino acids, wherein the hydrophobic substance is attractive to aromatic amino acids and has substantially no attraction to non-aromatic amino acids;    contacting the hydrophobic substance with a wash agent provided at a first flow rate to remove residual non-aromatic amino acids from the hydrophobic substance;    increasing the flow rate of the wash agent to a second flow rate to remove monocyclic aromatic amino acids from the hydrophobic substance to form a second fraction; and    contacting the hydrophobic substance with a release agent at a third flow rate to remove L-β-3 from the hydrophobic substance to form a third fraction.    
   
   
       32 . The process of  claim 31 , wherein said flow rates are volume normalized.  
   
   
       33 . The process of  claim 31 , wherein said providing comprises providing the aqueous solution at a flow rate of approximately 2 to 5 gallons per minute.  
   
   
       34 . The process of  claim 31 , wherein said contacting the hydrophobic substance with a wash agent comprises contacting the hydrophobic substance with water.  
   
   
       35 . The process of  claim 31 , wherein said contacting the hydrophobic substance with a wash agent provided at a first flow rate comprises providing the wash agent at a first flow rate of approximately 2 to 5 gallons per minute.  
   
   
       36 . The process of  claim 31 , wherein said increasing the flow rate of the wash agent to a second flow rate comprises increasing the flow rate to approximately 8 to 11 gallons per minute.  
   
   
       37 . The process of  claim 31 , wherein said contacting the hydrophobic substance with a release agent comprises contacting the hydrophobic substance with isopropyl alcohol.  
   
   
       38 . The process of  claim 31 , wherein said contacting the hydrophobic substance with a release agent at a third flow rate comprises providing the release agent at a flow rate of approximately 8 to 11 gallons per minute.  
   
   
       39 . The process of  claim 31 , further comprising flushing the resin to remove residual L-β-3 from the hydrophobic substance.  
   
   
       40 . The process of  claim 39 , wherein said flushing the resin comprises flushing the resin with water.  
   
   
       41 . The process of  claim 39 , wherein said flushing the resin comprises flushing the resin at a flow rate of approximately 8 to 11 gallons per minute.  
   
   
       42 . A process, comprising: 
 providing an aqueous solution of a mixture of amino acids;    contacting a hydrophobic substance with the aqueous solution to form a first fraction comprising non-aromatic amino acids, wherein the hydrophobic substance is attractive to aromatic amino acids and has substantially no attraction to non-aromatic amino acids;    contacting the hydrophobic substance with a wash agent provided at a volume-normalized flow rate to remove monocyclic aromatic amino acids from the hydrophobic substance to form a second fraction; and    contacting the hydrophobic substance with a release agent at a volume-normalized flow rate to remove L-β-3 from the hydrophobic substance to form a third fraction.    
   
   
       43 . The process of  claim 42 , wherein said contacting the hydrophobic substance with a wash agent comprises contacting the hydrophobic substance with water.  
   
   
       44 . The process of  claim 42 , wherein said contacting the hydrophobic substance with a release agent comprises contacting the hydrophobic substance with isopropyl alcohol.